Mineral oil additive



Patented Mar. 10, 1953 UNITED STATES Mort oFFicef Jeiifrey:H.;-Bartlett, estfieldfand Thomas Cross;

Jr., Union, N. J-., assignors he ent q mra a corporationof Delaware to Standard'Oil De-.

No Drawing. Application October 28,1949, SerialN0.'124, 256- a a which an additive has been incorporated to im- -prove the properties of the same;

Modern developments in the design of internal severe strain on the lubricants employed. In particular, the crankcasejoil 'is 'raised to a high temperature and -in the course of. its circulation throngh the engine is rapidlyexp'osed to air under conditions highly conducive to destructive oxidation. Oxidative breakdown of the oil results in the formation of acidic products which corrode bearing surfaces and do considerable harm to Q the engine generally. Furthermore, the metallic corrosion products have the effect of catalyzing further oxidative breakdown of the oil.

It is alsoknowh that in modern internal com- ,bustion engines, such as aviation gasoline engines operating at relatively high temperatures due to their high power output, or in high speed diesel engines due to incomplete combustion, piston rings have a tendency to become stuck in grooves. Lacquer and carbon formation appear to be the principal reasons for this occurrence. Moreover, scufiing of top lands due to the format- 'tion of hard carbon particularly whenusingfhigh v viscosity index 'oils may cause serious damage to lt has beenffciindiin accordance with the picsof a new additive, which may be described as a 19 Claims. (01.: 252F321?) v sludge in lubricating .combustion'engines, 'with increasing engine ,speedsIandlcompressiont ratios, have imposed a posed to :moisture or -humi-d.

oils, but are also useful, when added to lubricants, for the purpose of protecting exposed metallic surfaces of such engines against rusting when the same are e air. The additives are alsoq-usefuh generally -as anti-o idants.-; in

jmineraloil' products of all types,

- qIns-tead of. pentaerythri-tpl and alcoholsot :similar type, certain derivati-ves of these s -alcohols may likewise be employed in preparing the additives-ofthe present invention, Home;-

1 ample, dipentaerythritoland tripentaerythi itpl -in;which- R is a methylol group or an alkyl gronp .aE-romO-toZ and-in-which 1 tent; v nt pn, that destructive O idat OIL hydroxyl groups may be substituted by-aradical lubricating oils and deposition of carbon and lacquer may both be reduced to a considerable degree by the addition to the oil of a small amount product obtainedby reacting a sulfide of phos- 'phorus or other combinations of the elements sulfur and phosphorus with an ester of a polyhydriccalcohol containing a neo-carbon atom,

typified by pentaerythritol, such alcohol being fully esterified and the ester preferably contain ing at least one unsaturated organic acid radi- I cal. 'Metal salts of such products, when the metal is selected from the metals of group I or II of tives not only have the effect of reducing oxidamay be employed, as well as derivatives of all of such compounds obtained by reacting ethylene oxide or propylene oxide with the same, where there-is-introduced-into the molecule one or more oxygen atoms in the form of ether linkages and additional short carbon chains, in accordance with the well-known methods of forming-etheralcohols. I

The alcohols which maybe employed in the formation of the new additives may be defined in their broadest scope by the formula containing 1 to 3 -carbon atoms,;-B,' is am ethyl or e yl ro p .-.a d m an n are mb one or more of the of'the formula r f! Ilia ()o11'-o 1ori in'whi'ch R1 'and'Rz each represent hydrogen .or a methyl'group, at least one being'hydroge'n, and

. in which 11 is a number froml to 10. It is obvious the periodic table, may also beemployed to ad l lvantage, especially when the detergent effects of the additive are to be emphasized. These addi- (pentaglycerol),

that in the last formula prepresents the number of mols of ethylene oxide or propylene oxide which have been reacted with the hydroxyl group of the alcohol. Some of the more preferred alcohols coming within the above definitionare pentaerythritol, dipentaerythritol, tripentaerythritol, 2 methyl 2 methylol 1,3 propanediol 2,2-dimethyl 1,3 propanediol -(pentaglycol), tetra-(hydroxy ethylether), ,of

- dimethylollpentaerythritol, 3 methyl 2,2 butanol, and the like.

, of the elements sulfur and phosphorus.

venient to prepare. "iconvenientl y prepared by reacting the phos-. phorusand sulfur reaction product with metallic radicals are alike or in which they are different, 7

but it is highly desirable to employ esters in which at least one of the esterifying; acid radicals contains a double bond. Examples of. suitable acids include laurl'c, myrist'ic. palmitic, stearic, arachidic, behenic, oleic; eruci liholeic,

undecylenic and homologous acids; also naturally" occurrin fatty acids and mixtures of fatty acids.

such as those derived from coconut oil-,. palm oil, corn oil, soybean oil, fish oils, cottonseed oil, rapeseed oil, tallow andlard, also oxidized petroleum fractions and oxidized waxes, partially or completely hydrogenated acid'sof the abovetypes, unsaturated acids produced by the hydrogenation and dehydrogenation of waxes; stearic acid, naphthenicacids; and other acids of similar types. 7

The esters derived from the alcohols and: acids described above are reacted with. acombination It is preferable toemploy a sulfide. of phosphorus, such as PzSz; PiS's, P iSa; or P101, or mixtures thereof; but mixtures of elemental sulfur and elemental phosphorus may likewise be employed, in: which case it is preferable toemploy powdered sulfur and white phosphorus; Likewise, a mixture of one or more sulfides of phosphorus and elemental sulfur and/or elemental phosphorusmay be employed. The amounts of sulfur and phosphorus which are advantageously employed depend upon the number of doublebonds present the ester indouble-bondedhydrocarbon groups, and it is preferred, to react from :1 to 1 atom of phosphorusand 0.1 to 3 atoms of sulfur for each such double-bond on the ester molecule. In general, the higher proportions of phosphorus and sulfur or sulfide of phosphorus may be employed when the ester molecule contains saturated oil-solubilizing hydrocarbon groups. In general, the tempearture at which the reaction blithea sulfide of phosphorus or mixture of sulfur and? phosphorus with the ester is carried out is; mm 200 to 500 FL, and the time required ts-substantially complete the reaction is generaliy'from 1' to hours. It is generally" desirable to employ a solvent for the ester, in which case the solvent should be relatively inert to phosphorus and sulfur. Such solvents include, for example, benzene, o-dichlorbenzene, mineral oils; and the like. Inpreparing an additivefor a. mineral oil. it is usually convenient to employ suchiaimiheral cilia-s the mediumfor thereaction, and thus prepare a concentrate for convenient use in. blending with the oil;

As: stated above, the reaction products preas: described may be employed as such or in the: form of their metal salts. The metals employed arepreferably group II metals and the calcium. salts: are: particularly desirable and com Such metal salts may be oxides or hydroxides. Such metallic compounds may be added to the reaction mixture in which 4 the phosphorus and. sulfur reaction products are formed, and the mixture heated to a temperature of the range of 50-400 F.

The additives of the present invention are preferably added to mineral oils in proportions ranging from 0.01% to the proportion being preferably about 1.0 to 5.0% when employed as corrosion inhibitors and detergents in mineral lubricating oils. The proportions giving the best results will vary somewhat according to the nature. of the additive-and the: specific quality characteristics of the oil to be improved by the use of the additive. For commercial purposes. when the additives are to be employed in minerallubricating oils, it is convenient to prepare concentrated oil solutions in which the amount of additive the: compositions. ranges from to by weight, and to transport and. store them in such form. In preparing lubricating oil compositions for use as crankcase lubricants, the

' additive concentrate is merely blended with the base oil in the required amount.

- Below are given detailed descriptions of preparations of several'examples of mineral oil additives. of; the: type described above as well as various: laboratory tests which were applied; to determine? their effectiveness when employed in lubricating oil compositions; It is to. be understood 'that; these examples: are given to illustrate the present invention and are: not to be construed as limiting the scope thereof in: any way.

ritol was added slowly over' a period of. 10

minutes. The mixture" was then heated at 446 F. for hours. The product was found to have a neutralization number of 12111.

(b) 400 gms. (0.33 mol) of the mixed oleatestearate ester of pentaerythritol, prepared as described above, was placed in a 1-liter round bottom flask equipped with a mechanical stirrer. A slow stream of nitrogen was bubbled through the product and the temperature of the contents of'the flask was. raised to. 250 F. 317.3 ms. (0.17 mol) of phosphorus pentasulfide was. added slowlyover a period. of 1 hour... aiter which the mixture was heated at. 300? F. for 3v hours. and

filtered through a. filter aid.v The product was blended in an extracted. Mid-Continent mineral oil. of S. A. E.-20 viscosity grade to form a 40% by weight concentration. This concentrate showed thafollowing analysis Ehosphorus percent 0.66

Sulfur (10;... 2.27

Neutralization No 16318 Example 2 product had a neutralization number of 29.07.

Ch) 200 gms. (0.1 7 mol) of the aboveester was placed in a small 3-necked flask equipped with a sane. Nitrogen was bubbled in 1dw1y"aha the contents heated to 248 F.. after which 186 gms. (0.084 mol) of P285 was added over a period of 1 hour. The temperature was then raised to 302 F. and held at. this point for 3 hours. A filter-- aid was added and the product filtered hot.

6 was used for each mol of pentaerythritol tetraoleate.

' Analysis: Percent Phosphorus 1.37

Analysis:

Phosphorus percent 0.25 Sulfur do 6.37. Neutralization No. 5.14

Example 3 (a) 2225 gms. (7.88 mols) of oleic acid wa placed in a -liter 3-necked flask and heated to 302 F. while bubbling nitrogen through the mixture. '23:; gms. (1.75 mols) of pentaerythritol was then added over a period of minutes, after which the temperature was raised gradually over a period of 1 hour to a temperature of 446 F. and

" held at this point for 4 hours additional. The

product was dissolved in 3 l. of toluene and the solution given three washings with 5% aqueous sodium carbonate solution and three washings with water, and finally evaporated on a steam bath in the presence of nitrogen and filtered through celite. The product consisted of pentaerythritol tetraoleate.

Analysis:

Neutralization No. 1.13 Saponification No. 181.9 Bromine No 50 (b) 200 gms. (0.168 mol) of the pentaerythritol I tetraoleate prepared as described above and 328 gms. of a solvent extracted Mid-Continent neutral distillate oil of 44.1 seconds viscosity (Saybolt) at 210 F. was charged into a 2-liter 3- necked fiask equipped with a stirrer, a nitrogen inlet tube, thermometer, and gas exit tube. After heating the mixture to 250 F. 18.6 gms. (0.084

' mol) of P285 was added and heating continued to 300 F., at which point it was maintained for 5 hours. The product was filtered while hot through celite, leaving about 2 gms. of unreacted P2S5. The product was considered as containing active ingredient.

- Analysis: Percent Phosphorus 0.94

Sulfur 2.18

Example 4 A 2-liter 3-necked flask equipped as in Example 3(b) was charged with 200 gms. (0.168 mol) pentaerythritol tetraoleate (prepared as describedin Example 3(a) and 344 gms. of solvent extracted dient. Analysis Percent Phorsphorus 0.84

Sulfur 335 Example 5' A preparation was made. according to .the.

except that 0.75 mol of Pass method or Example 3,

Sulfur 3.32

I Example 6 h (a) 229 gms. (0.9'mol) dipentaerythritol, 1654 gms. (5.9 mols) oleic acid, 10 cc. xylene, and 1 gm. calcium hydroxide were charged into a 3-liter 3-necked flask equipped with stirrer, water trap,

with 1500 cc. toluene and the solution given three 77 reflux condenser, thermometer, and nitrogen inlet tube, and the mixture refluxed at 356-446 F. for hours, during which time 89 cc. of water was collected. The product was then diluted washings with 5% aqueous sodium hydrox'ide and three washings with water and evaporated on the steam bath in the presence of nitrogen. The product consisted of dipentaerythritol hexaoleate.

Analysis:

Neutralization No 0.35 Saponificatoin No 126.8 Acetyl No 2.0

(b) The product obtained in (a) was reacted with PzSs, using 200 gms. (0.109 mol) of dipentaerythr itol hexaoleate, 17.9 gms. (0.081 mol) of Pzss and 328 gms. of mineral oil solvent. The preparation was carried out in the manner described in Example 3(1)), the solvent being the same. The resulting product contained about 40% active ingredient.

Analysis: Percent Phosphorus 092 Sulfur 2.29

Example 7 Dipentaerythritol hexaoleate (prepared as described in Example 6 (0)) was reacted with sulfur and P285 in the proportions of 3 mols of sulfur and 0.75 mol of P285 for each mol of the ester, the conditions of the preparations being the same as in Example 4, in which 200 gms. dipentaerythritol hexaoleate, 342 gms. of oil solvent, 10.3 gms. sulfur, and 17.9 gms. P2S5 were used. The product contained about 40% active ingredient.

Analysis: r Percent Phosphorus 0,85 Sulfur 3.85

Example 8 100 gms. (0x18411101) 'ofpentaerythritol tetrav linoleate (a commercial product) ,-9.4 gms.- 0.042

mol) P2S5 and 164 gms. of the mineral oil solvent employed in Example-3(5)- were reacted under conditions described in Example 3 (b) The product contained about 40%active ingredient.

Analysis Percent Phosphorus 0.89 Sulfur 2.12

Example 9 gms. (0.073 mol) of the tetraoleate of pentaerythritol hydroxy ethyl ether (commercial product), 8.1 gms. (0.037 mol) of Pass, and 162 gms. of the solvent employed in Example 3(b) were reacted under the conditions of Example 3(b), the product containing about 40% active ingredient. ,IAhaly'sisi Y Percent Phosphorus 0.81. sulfur; "L.-- "2.17

j Analysis: Percent, Ash' 1.70 Calcium 0131 Example 11 The calcium salt of the product of Example 3 "(-b')- was prepared in the manner described in Example 10, using 200 g ms. of: the. reactionprod- I *uctand gm's. of calcium hydroxide.

. Analysis; Percent Ash 0.63

Calcium g Example 12 The calcium salt. of. the product of Example 4 was preparedinthe manner described in Example.

. 10,.using the same weight-proportions of. reaction product and calcium hydroxide.

Exa'mple 1'3 The calcium salt of theproduct of Example 5 V was similarly prepared.

Analysis: 7 Percent Ash 0.41

Calcium 0.034

Example 14 The;- calcium: salt of the product of Example 6 (=11) was similarly prepared;-

' Analysis: Percent Ash 0.10 Calcium 0.012

Example 15 The calcium saltof the product of Example 7 was similarly prepared.

Analysis: Percent I Ash 0.07

Calcium 0.007

Example 16:

Analysist Percent Ash 1.26 Potassium 0.50

Example 17.-Carbon black dispersion test In this test which is used to measure' the'dispersive power of the lubricating oils, 500 cc; of 2.21%? blend of theactive ingredient in a-solvent extracted Mid-Continent paraflinic oil of 52 seconds viscosity (Saybolt) at 210 F. is agitatedwith 6 by Weight of carbon black and. allowed tosettle for 24 hours at 200 F. Foncomparison a similar amount of unblended base-0111's simi- To thiswas: added ucts of- Example- 1;( b) and. Example 16- Since these products-are 40% oil concentrates,.2.5'% by weight ot each was. employed in preparing the blendsfor the test.. The results are shown in Table I,

TABLE. I

Observation Aiter'24 Hours Oil z f Ccsvoi" g Cos. of

Clear Oil Dispersion BaseOil Y 160 340 Base Oil+l% Pent'aerythritol oleatestearate=1 zS5 reaction'product r 0 500 Base 01'l.+1%;Potassiumsalt o pentaerythrit'oll oleatc-stearatc-P ss reaction product. M. 0'- 500 7 Example 18.-I'ndiana oxidation test In this test a. glass plate is inserted in the test oil and thelweight of the varnish film deposited I onthe. plate; during: 48 hours: is measured. The

011: during? the test is held at 341 VR, and air is passed through the oil at the rate of 10 liters per hour; Thistest was applied to a base oil consisting ofa. solvent extracted: Mid-Continent oil of S. A. E.20 grade and to a blend of this oil and 2.5% of the 40% concentrate product of Example 10. The results are as follows;

' TABLE II Varnish on Oil Glass Plate Base-:Oil -3.0 'Base Oil+2.5% product of Example 10 j 1. 5

Exampleir-Labomtory bearing corrosion test Blends. were made of the products (40% concentrates in oil). of' Examples 1 to 15, inclusive, in a. lubricating oil base consisting of a, well refined; solvent extracted paraffinic mineral lubricating oil of S. A. E.-20 viscosity grade in such proportions that in. each. case a blend was prepared containing 0.25% of the active ingredient; These blends and a sample of the unblended base oil were submitted to a corrosion testdesigned to test the. eiiectiveness of. the additive in inhibiting, corrosion of a typical copperlead bearing.

ere te The test was applied to the prod- 15 Table III. below as In this test 500 cc. of" the oil was. placed in a glass oxidation. tube (113. inches. long and 2% inches in diameter). fitted. at the bottom with a My air inlettube perforated to facilitate air distribution. The. oxidation. tube was then immersed in a heatingbath so that the oil temperature was maintained at 325 F. during the test. 'Ilwo quarter secions of automotive bearings-of. copper-lead alloy of known weight having. a. total area of. 25' sq. cm. were attached to oppositesides of a stainless steel rod which was then immersed in the test oil and rotated. at 600 R... P M., thus providing sufli'cient agitation of thesampleduring the test. Air was then blown through theoil. at the rate of 2 cu. ft. per hour. At the end of each 4-hour period the bearings were removed, washed with naphtha and weighed todetermine the amount of loss by corrosion. The hearingswere then repolished (to increase the severity of the test)-, reweighed, and then subjected to the testfor additional 4-hour periods in like manner. The results are given in corrosion life, which indi- 9 dates the number of hours required for the bearlugs to lose 100 mg. in weight, determined by interpolation of the data obtained in the various periods.

Example 20.-Copper strip test Each of the products of Examples 3 to 15 was blended in a lubricating oil base consisting of a solvent extracted Mid-Continent neutral distillate of 44.1 seconds viscosity (Saybolt) at 210 F., in an amount suificient to form a blend containing 0.75% of active ingredient. These blends and a sample of the unblended base oil were submitted to a copper strip corrosion test which 10 cracking coil tar fractions and coal tar or shale oil distillates may also be used. Also, for special applications, animal, vegetable or fish oils or their hydrogenated or voltolized products may be employed in admixtures with mineral oils.

For the best results of base stock chosen should normally be an oil which with the new additive present gives the optimum performance in the service contemplated. However, since one advantage of the additives is that their use also makes feasible the employment of less satisfactory mineral oils, no strict rule can be laid down for the choice of the base stock. The additives are normally sufficiently soluble in the base stock, but

was a modification of C. R. C. method L-16-445. 15 in some cases auxiliary solvent agents may be This method comprises immersing a polished used. The lubricating oils will usually range metallic copper strip in the oil blend to be tested from about 40 to 150 seconds (Saybolt) viscosity for periods of and 3 hours at 212 F. and notat 210 F. The viscosity index may range from ing the extent of staining. Numerical ratings to 100 or even higher. from 1 to 10 denote discoloration ranging from 20 Other agents than those which have been no staining to a black surface film, respectively. mentioned may be present in the oil composi- The results of the tests described in Examples tion, such as dyes, pour point depressants, heat 19 and 20 are given in Table 111, which follows. thickened fatty oils, sulfurized fatty oils, sludge TABLE III B cCopper StEipt Mol Ratio, Mol Ratio, eamlg Additive Prep. Ester Treated Ester/Pas Ester/s figrgfiirosn) $6 Ht. 3 Hr.

None None -Q 9 2 2 Example1(b) Pentaerythritol O1eate-Stearate l: .5 21 Example2(b) Pentaerythritolstearate l: .5 l3 Example3 (b) Pentaerythritol Tetraoleate l: .5 l4 2 2 Example4 dO 1: .5 l8 2 2 Example 5-.. 1: .75 18 3 3 Example 6 l: .75 14 4 7 Example 7.-- d0 l: .75 20 2 2 Example 8..- Pentaerythritol Tetralinoleate l: .5 l4 3 7 Example 9 Tetraoleate of Penta-erythritol Hy- 1: .5 l3 3 3 droxy Ethyl Ether.

Example 10 Pentaerythritol Oleate-Stearate. l: .5 22 Example 11 Pentaerythritolletraoleate 1: .5 17 3 3 Example 12 i0 l: .5 1:2 14 2 2 Example 13 0 l: .75 32 3 4 Example 14 Dipentaerythritol Hexaoleate 1: .75 13 4 7 Example 15 I-.- 0 1: .75 1:3 18 2 3 Example 16 Pentaerythritol O1eate-Stearate.-.. 1: .5 34

1 Calcium salt.

2 Potassium salt.

The products of the present invention may be dispersers, anti-oxidants, thickeners, viscosity inemployed not only in ordinary hydrocarbon lubricating oils but also in the heavy duty type of lubricating oils which have been compounded with such detergent type additives as metal soaps, metal petroleum sulfonates, metal phenates, metal alcoholates, metal alkyl phenol sulfides, metal organo phosphates, phosphites, thiophosphates and thiophosphites, guanidine salts, metal xanthates and thioxanthates, metal thiocarbamates, and the like. Other types of additives, such as phenols and phenol sulfides, may also be present.

The lubricating oil base stocks used in the compositions of this invention may be straight mineral lubricating oils or distillates derived from parafiinic, naphthenic, asphaltic or mixed base crudes, or, if desired, various blended oils may be employed as well as residuals, particularly those from which asphaltic constituents have been carefully removed. The oils may be refined by conventional methods using acid, alkali and/or clay or other agents such as aluminum chloride, or they may be extracted oils produced by. solvent extraction with solvents such as phenol, sulfur dioxide, etc. Hydrogenated oils or white oils may be employed as well as synthetic oils prepared, for example, by the polymerization of olefins or by the reaction of oxides of carbon with hydrogen or by the hydrogenation of coal or its products. In certain instances 75 I I I in which R is a member of the group consisting of methylol radicals and alkyl radicals containing 1 to 3 carbon atoms, R. is a member of the group consisting of methyl and methylol radicals, and m and n are numbers from 0 to 2, said ester being derived from said alcohol by substituting all of the free hydroxyl groups thereof with radicals of monobasic carboxylic acids containin 8 to 30 carbon atoms per molecule; and (B) salts of said products and a metal selected from groups I and II of the periodic table; the re-.

actants beingemployed in such proportions that from 0.2 to 0.4 atom of phosphorus and 0.5 to 1 atom of sulfur are present for each acid radical present in the ester, and the reaction being conducted at a temperature in the range of about 200 to about 300 F.

2. A composition according to claim 1 in which the. mineral oil is a lubricating oil fraction.

3. A mineral oil containing dissolved therein 0.01 to 15% of the product-obtained by reacting a combination of the elements sulfur and phosphorus with an ester of an alcohol of the formula R HQCHr-CHzOH in which R is a member of the group consisting of methylol groups and alkyl groups containing 1 to 3 carbon atoms, and R, is a member of the group consisting of methyl and methylol groups, said ester being derived from said alcohol by substituting all of the free hydroxyl groups with radicals of monobasic carboxylic acids containing 8 to 30 carbon atoms per molecule, at least one such radical containing a double bonded hydrocarbon chain, the reactants being employed in such proportions that from 0.1 to 1 atom of phosphorus and 0.1 to 3 atoms of sulfur are present for each double bonded hydrocarbon chain in the ester molecule, and the reaction being conducted at a temperature in therange of about 200 to about 300 F.

4. A composition according to claim 3 in which the mineral oil is a lubricating oil fraction.

5. A composition according to claim 3 in which the alcohol from which the ester is derived is pentaerythritol.

6. A composition according to claim in which all of the acid radicals of the ester are unsaturated radicals.

7. A composition according to claim 5 in which the ester is pentaerythritol tetraoleate.

8. A mineral lubricating oil containing dissolved therein 0.01 to 15% of a product obtained by reacting about one molecular proportion of pentaerythritol tetraoleate with about 0.5 to 0.75 molecular proportion of phosphorus pentasulfide at a temperature in the-range of about 200 to about 300 F.

9; A mineral lubricating oil containing dissolved therein 0.01 to 15% of a product obtained by reacting one molecular proportion of pentaerythritol tetraoleate with 0.5 molecular proportion of phosphorus pentasulfide at a temperature of 250 to 300 F.

- 10. A mineral lubricating oil containing dissolved therein 0.01 to 15% of a product obtained by reacting one molecular proportion of dipentaerythritol hexaoleate with 0.75 molecular proportion of phosphorus pentasulfide at a temperature of about 250 to 300 F.

11. A composition according to claim 3 in which the additive is a group II metal salt of the reaction product defined in said claim.

, 12. A composition according to claim 11 in which the metal is calcium.

' 13. A mineral lubricating oil containing dissolved therein 0.1 to 15% of the calcium salt of a product obtained by reacting about one molecu- 2,631, rec

I 12" lar proportionrof pentaerythritol 'tetrao-leate with about 0.5 to 075. molecular proportion of phosphorus pentasulfide at a temperature in the range of about 200 to about 300 F.

14. A mineral lubricating oil containing dissolved therein 0.01 to 15% of the. calcium salt of the product obtained by reacting one molecular proportion of pentaerythritol tetraoleate with 0.75 molecular proportion of phosphorus pentasulfide at a temperature of about 250 to 300 F.

15. A composition consisting essentially of a mineral lubricating oil and an additiveas defined.

in claim 1, the amount of said additive in the. composition being 25 to 50 by weight.

16. A composition consisting essentially of a mineral lubricating oil and an additive as defined in claim 14, the amount of said additive in the: composition being 25 to 50 by Weight.

17. As a new composition of matter a. member of the class consisting of: (A) the products obtained by reacting a combination of the elements sulfur and phosphorus with an ester of an alcohol selected from the group consisting of alcoholsof the formula in which R is a member of the group consisting of methylol radicals and alkyl radicals containing 1 to 3 carbon atoms, R is a member of the group consisting of. methyl and methylol radicals, and m and n are numbers from 0 to 2, said ester being; derived from said alcohol by substituting all ofthe free hydroxyl groups thereof with radicals of: monobasic carboxylic acids containing 8 to 30 carbon atoms per molecule; and (B) salts of said" products and a metal selected from groups I and II of the periodic table; the reactants being employed in such proportions that from 0.2 to 0.4 atom of phosphorus and from 0.5 to 1 atom of sulfur are present for each acid radical in the ester molecule, and the reaction being conducted at a temperature in the range of about 200 to about 300 F.

18. As a new composition of matter a product obtained by reacting a sulfide of phosphorus with pentaerythritol tetraoleate, the. proportions of the reactants being such that about 0.2 to about, 0.4 atom of phosphorus and 0.5 to. 1, atom of sulfur are present for each acid radical in the ester molecule, the reaction being conducted at'a temperature in the range of about 200 to about 300 F.

19. As a new composition of matter the calcium salt of the reaction product as defined in claim 18.

JEFFREY H. BARTLETT. THOMAS CRQSS, J R.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

1. A MINERAL OIL CONTAINING DISSOLVED THEREIN 0.01 TO 15% OF A MEMBER OF THE CLASS CONSISTING OF: (A) THE PRODUCTS OBTAINED BY REACTING A COMBINATION OF THE ELEMENTS SULFUR AND PHOSPHORUS WITH AN ESTER OF AN ALCOHOL SELECTED FROM THE GROUP CONSISTING OF ALCOHOLS OF THE FORMULA 